Heating of multi‐species upflowing ion beams observed by Cluster on March 28, 2001
Heating of multi‐species upflowing ion beams observed by Cluster on March 28, 2001
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2001年3月28日Cluster观测到的多物种上流离子束的加热
DOI：
10.26464/epp2019022
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发表时间：
2019
影响因子：
2.9
通讯作者：
Xiong Ying
中科院分区：
文献类型：
--
作者：
Yu Fangbo;Fu Suiyan;Sun Weijie;Zhou Xuzhi;Xie Lun;Liu Han;Zhao Duo;Zhao Shaojie;Li Li;Zhang Jingwen;Wu Tong;Xiong Ying
2001年3月28日，星系团卫星观测到三束连续流出的离子束。这些离子束由H+、He+和O+离子组成，能谱具有三个倒V型结构，一般认为它们是通过U型势结构加速产生的。通过消除背景离子布居数，并采用Maxwelling拟合，我们发现来自势结构中心的离子比来自两侧的离子具有更高的温度。与H+相比，O+和He+的温度较高，表明重离子优先被加热;我们进一步推断O+和He+离子的加热效率在U形势结构的中心和边缘之间存在差异。基于俯仰角观测的估计表明，加热也可能发生在极光加速区（AAR）的上边界以上的高度，这些光束通常被认为是形成的。
Cluster satellites observed three successive outflowing ion beams on 28 March, 2001. It is generally accepted that these ion beams, composed of H+, He+, and O+ ions, with three inverted-V structures in their energy spectra, are produced by acceleration through U-shaped potential structures. By eliminating the background ion population and employing Maxwelling fitting, we find that ions coming from the center of the potential structure have higher temperature than those from the flanks. Higher temperature of O+ and He+ compared to that of H+ indicates that heavy ions are preferentially heated; we further infer that the heating efficiencies of O+ and He+ ions differ between the center and edges of the U-shaped potential structures. Estimation based on pitch angle observations shows that heating may also occur at an altitude above the upper boundary of the auroral acceleration region (AAR), where these beams are generally thought to be formed.